Infant - Newborn Development

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Behavior

The behavior of the newborn is characterized by 6 states of consciousness: quiet sleep, active sleep, drowsy waking, quiet alert, fussing, and active crying. The ability to move smoothly from one state to another is one of the most reliable signs of neurologic maturity and integrity. Heart rate, breathing, muscle tone, and body movements vary with each state.

Many physiologic functions are not stable in the first months after birth. This variability is normal and differs from infant to infant. Temperature control, skin color, stooling, yawning, gagging, hiccupping, and vomiting are easily affected by stress and stimulation.

Periodic breathing, in which breathing starts and stops again, is normal and is not a sign of SIDS (sudden infant death syndrome). Some infants will vomit after each feeding but have no organic pathology and continue to gain weight and develop normally.

Other infants grunt and groan distressfully while stooling but produce soft, blood-free stools and growth and feeding remain good. This is due to immature abdominal muscles for pushing and does not require any intervention.

Sleep/wake cycles are extremely variable and do not stabilize until 3 months old. These cycles occur in random intervals of 30 to 50 minutes after birth and gradually increase as the infant matures. By 4 months old, most infants will have one 5-hour period of uninterrupted sleep.

Breast-fed infants will feed about every 2 hours. Formula-fed infants should be able to go 3 hours between feedings. During periods of rapid growth, they may feed more frequently.

Giving the child water is not necessary! Adequate hydration is indicated by 6 to 8 wet diapers in a 24-hour period. Teaching the infant to suck a pacifier or his or her own thumb provides comfort between feedings.